using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Collections.Generic;

namespace FreeFlow.Administration
{
	/// <summary>
	/// A collection of custom variables.
	/// </summary>
	public sealed class ColumnCollection : DatabaseAware, IRefreshable, IList,
    IBindingList, IEnumerable<Column>
	{
    private List<Column> variables;
    private string mapTableName;
    private bool includeEFolderId;

    internal ColumnCollection(Server server, string mapTableName, bool includeEFolderId)
      : base(server)
		{
      this.mapTableName = mapTableName;
      this.includeEFolderId = includeEFolderId;
		}

    private void ReadVars()
    {
      if (variables == null)
      {
        // get variables
        variables = new List<Column>();
        using (IDataReader reader = Server.ExecuteReader(
          string.Format("SELECT * FROM {0} WHERE 1=0", mapTableName)))
        {
          for (int i = 0; i < reader.FieldCount; i++)
          {
            if ((reader.GetName(i) != "EFOLDERID") || includeEFolderId)
            {
              Column var = new Column(Server, reader, i, mapTableName);
              variables.Add(var);
            }
          }
        }

        variables.Sort();
      }
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
      ReadVars();
      return variables.GetEnumerator();
    }

    #region IEnumerable<Variable> Members

    /// <summary>
    /// Returns an enumerator that iterates through the collection.
    /// </summary>
    /// <returns>
    /// A <see cref="T:System.Collections.Generic.IEnumerator`1"/> that can be used to iterate through the collection.
    /// </returns>
    public IEnumerator<Column> GetEnumerator()
    {
      ReadVars();
      return variables.GetEnumerator();
    }

    #endregion

    /// <summary>
    /// Gets the number of variables in this collection.
    /// </summary>
    public int Count
    {
      get
      {
        ReadVars();
        return variables.Count;
      }
    }

    /// <summary>
    /// Gets the <see cref="Column"/> at the specified index.
    /// </summary>
    public Column this[int index]
    {
      get
      {
        ReadVars();
        return (Column)variables[index];
      }
    }

    /// <summary>
    /// Gets the <see cref="Column"/> with the specified name.
    /// </summary>
    /// <param name="name">The name of the variable to retrieve.</param>
    public Column this[string name]
    {
      get
      {
        for (int i = 0; i < Count; i++)
        {
          if (this[i].Name == name)
            return this[i];
        }

        return null;
      }
    }

    /// <summary>
    /// Removes the specified variable from the collection and the database.
    /// </summary>
    /// <param name="variable">The variable to remove.</param>
    public void Remove(Column variable)
    {
      ReadVars();
      if (variables.Contains(variable))
      {
        variable.Delete();
        variables.Remove(variable);
      }
    }

    #region IRefreshable Members

    /// <summary>
    /// Refreshes the list of variables.
    /// </summary>
    public void Refresh()
    {
      variables = null;
    }

    #endregion
    #region IList Members

    /// <summary>
    /// Gets a value indicating whether the <see cref="T:System.Collections.IList"/> is read-only.
    /// </summary>
    public bool IsReadOnly
    {
      get
      {
        return true;
      }
    }

    object IList.this[int index]
    {
      get
      {
        ReadVars();
        return variables[index];
      }
      set
      {
        throw new NotSupportedException(readOnlyListMessage);
      }
    }

    /// <summary>
    /// Removes the <see cref="T:System.Collections.IList"/>
    /// item at the specified index.
    /// </summary>
    /// <param name="index">The zero-based index of the item to remove.</param>
    /// <exception cref="T:System.ArgumentOutOfRangeException">
    /// 	<paramref name="index"/> is not a valid index in the <see cref="T:System.Collections.IList"/>.</exception>
    /// <exception cref="T:System.NotSupportedException">
    /// 	<para>The <see cref="T:System.Collections.IList"/> is read-only.</para>
    /// 	<para>-or-</para>
    /// 	<para>The <see cref="T:System.Collections.IList"/> has a fixed size.</para>
    /// </exception>
    public void RemoveAt(int index)
    {
      ReadVars();
      Column var = variables[index];
      Remove(var);
    }

    void IList.Insert(int index, object value)
    {
      throw new NotSupportedException(readOnlyListMessage);
    }

    void IList.Remove(object value)
    {
      Remove((Column)value);
    }

    /// <summary>
    /// Determines whether the <see cref="T:System.Collections.IList"/> contains a specific value.
    /// </summary>
    /// <param name="value">The <see cref="T:System.Object"/> to locate in the <see cref="T:System.Collections.IList"/>.</param>
    /// <returns>
    /// 	<see langword="true"/> if the <see cref="T:System.Object"/>
    /// is found in the <see cref="T:System.Collections.IList"/>; otherwise, <see langword="false"/>.
    /// </returns>
    public bool Contains(object value)
    {
      ReadVars();
      return variables.Contains((Column)value);
    }

    void IList.Clear()
    {
      throw new NotSupportedException(readOnlyListMessage);
    }

    /// <summary>
    /// Determines the index of a
    /// specific item in the <see cref="T:System.Collections.IList"/>.
    /// </summary>
    /// <param name="value">The <see cref="T:System.Object"/> to locate in the <see cref="T:System.Collections.IList"/>.</param>
    /// <returns>
    /// The index of <paramref name="value"/> if found in the list; otherwise, -1.
    /// </returns>
    public int IndexOf(object value)
    {
      ReadVars();
      return variables.IndexOf((Column)value);
    }

    int IList.Add(object value)
    {
      throw new NotSupportedException(readOnlyListMessage);
    }

    /// <summary>
    /// Gets a value indicating whether the <see cref="T:System.Collections.IList"/> has a fixed size.
    /// </summary>
    public bool IsFixedSize
    {
      get
      {
        return true;
      }
    }

    #endregion
    #region ICollection Members

    /// <summary>
    /// Gets a value
    /// indicating whether access to the <see cref="T:System.Collections.ICollection"/> is synchronized
    /// (thread-safe).
    /// </summary>
    public bool IsSynchronized
    {
      get
      {
        return false;
      }
    }

    /// <summary>
    /// Copies the elements of
    /// the <see cref="T:System.Collections.ICollection"/> to an <see cref="T:System.Array"/>, starting at a particular <see cref="T:System.Array"/> index.
    /// </summary>
    /// <param name="array">The one-dimensional <see cref="T:System.Array"/> that is the destination of the elements copied from <see cref="T:System.Collections.ICollection"/>. The <see cref="T:System.Array"/> must have zero-based indexing.</param>
    /// <param name="index">The zero-based index in <paramref name="array"/> at which copying begins.</param>
    /// <exception cref="T:System.ArgumentNullException">
    /// 	<paramref name="array"/> is <see langword="null"/>.</exception>
    /// <exception cref="T:System.ArgumentOutOfRangeException">
    /// 	<paramref name="index"/> is less than zero.</exception>
    /// <exception cref="T:System.ArgumentException">
    /// 	<para>
    /// 		<paramref name="array"/> is multidimensional.</para>
    /// 	<para>-or-</para>
    /// 	<para>
    /// 		<paramref name="index"/> is equal to or greater than the length of <paramref name="array"/>.</para>
    /// 	<para>-or-</para>
    /// 	<para>The number of elements in the source <see cref="T:System.Collections.ICollection"/> is greater than the available space from <paramref name="index"/> to the end of the destination <paramref name="array"/>.</para>
    /// </exception>
    /// <exception cref="T:System.InvalidCastException">The type of the source <see cref="T:System.Collections.ICollection"/> cannot be cast automatically to the type of the destination <paramref name="array"/>.</exception>
    public void CopyTo(Column[] array, int index)
    {
      ReadVars();
      variables.CopyTo(array, index);
    }

    void ICollection.CopyTo(Array array, int index)
    {
      CopyTo((Column[])array, index);
    }

    /// <summary>
    /// Gets an object that
    /// can be used to synchronize access to the <see cref="T:System.Collections.ICollection"/>.
    /// </summary>
    public object SyncRoot
    {
      get
      {
        return null;
      }
    }

    #endregion
    #region IBindingList Members

    void IBindingList.ApplySort(PropertyDescriptor property, ListSortDirection direction)
    {
      ReadVars();
      sortProperty = property;
      sortDirection = direction;
      variables.Sort(new Comparer<Column>(sortProperty, sortDirection));
    }

    private PropertyDescriptor sortProperty;
    PropertyDescriptor IBindingList.SortProperty
    {
      get
      {
        return sortProperty;
      }
    }

    bool IBindingList.SupportsSorting
    {
      get
      {
        return true;
      }
    }

    bool IBindingList.IsSorted
    {
      get
      {
        return (sortProperty != null);
      }
    }

    void IBindingList.RemoveSort()
    {
      sortProperty = null;
    }

    private ListSortDirection sortDirection;
    ListSortDirection IBindingList.SortDirection
    {
      get
      {
        return sortDirection;
      }
    }

    #region not implemented 
    int IBindingList.Find(PropertyDescriptor property, object key)
    {
      return 0;
    }

    bool IBindingList.AllowRemove
    {
      get
      {
        return false;
      }
    }

    bool IBindingList.SupportsSearching
    {
      get
      {
        return false;
      }
    }

    private ListChangedEventHandler listChanged;
    event ListChangedEventHandler IBindingList.ListChanged
    {
      add { listChanged += value; }
      remove { listChanged -= value; }

    }

    bool IBindingList.SupportsChangeNotification
    {
      get
      {
        return false;
      }
    }

    object IBindingList.AddNew()
    {
      return null;
    }

    bool IBindingList.AllowEdit
    {
      get
      {
        return false;
      }
    }

    void IBindingList.RemoveIndex(PropertyDescriptor property)
    {
    }

    void IBindingList.AddIndex(PropertyDescriptor property)
    {
    }

    bool IBindingList.AllowNew
    {
      get
      {
        return false;
      }
    }

    #endregion
    #endregion
  }
}
